It says that you want to start activity with action "se.copernicus.activity.MainActivity". But you don't want that. You want to start activity of class se.copernicus.activity.MainActivity. These are two different things!

And now look at error message:

No Activity found to handle Intent { act=se.copernicus.activity.MainActivity }

Notice the act part in error message, it stands for Action. This means that Android can not resolve any activity for action "se.copernicus.activity.MainActivity". This only proves my previous point.

Instead of treating your class name as action, you need to create correct Intent with empty action value, but with correct Activity class name (more precisely with correct Component Id). So you actually need to create Intent using another Intent constructor: